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[English]
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- Accepted Version
Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission.
(Original Version)

Abstract

Detailed biostratigraphic sampling of the Lower Ordovician Boat Harbour and Catoche formations in the Boat Harbour - Cape Norman area of western Newfoundland has yielded hitherto unrecorded trilobite faunas so far unparalleled in richness and diversity anywhere in the Appalachians. -- Thirty species are systematically treated. Three new genera are proposed (Randaynia, Magnusnasus and Parapeltabellia). Seventeen species are new (Leiostegium proprium, Randaynia saundersi, R. langdoni, Hillyardina minuspustulata, H. levis, Hystricurus pseudoculilunatus, Magnusnasus proprius, Parahystricurus smithiae, Bolbocephalus stevensi, Jeffersonia angustimarginata, Parapeltabellia boatharbourensis, Peltabellia knighti, P. pseudopeltabella, Strigigenalis brevicaudata, Grinnellaspis newfoundlandensis, Uromystrum forteyi and Benthamaspis hintzei). Hyperbolochilus Ross is a junior synonym of Hillyardina Ross. -- Five new biostratigraphic zones are proposed, three of which are based on trilobites. These zones, in ascending order, are as follows: 1) Barren Interzone I, 2) Randaynia saundersi Assemblage Zone, 3) Barren Interzone II, 4) Strigigenalis brevicaudata Range Zone and 5) Strigigenalis caudate Range Zone. These zones are correlated with the standard trilobite zonation of the proposed Ibexian Series as well as the stages of the classical Canadian Series. -- A major Early Ordovician (Late Tremadoc - Early Arenig) faunal and sedimentological break is documented in western Newfoundland. The disconformity represented by a solution surface and pebble horizon is documented faunally by the absence of Ross-Hintze trilobite zone G1. This break is correlated with comparable breaks in the four major trilobite provinces which then existed, and it is proposed that these breaks are related to a world-wide Late Tremadoc - Early Arenig regressive event followed by a Early Arenig transgressive event.